Lee Smolin

TIME REBORN

From the Crisis of Physics to the Future of the Universe

Book review by Anthony Campbell. The review is licensed under a Creative
Commons Licence.
Smolin is a physicist who is probably best known for his theory of the
Darwinian evolution of universes. We are
invited to picture black holes continually giving birth to new
universes, in many of which new black holes will form to spawn further
universes in their turn. This process is supposed to be influenced by
Darwinian selection to produce universes with more black holes and
ever-increasing complexity.

That idea gave a central role to time, and in the present book Smolin
takes this further. The idea that time is unreal, an illusion, is
ancient and widespread. Truth, justice, scientific laws, and the divine
realm are often said to be outside time. This was Plato's view and it
was also held by Einstein. Smolin, in contrast, thinks that time is
utterly real. In fact, it is the most real aspect of our perception of
the world.

Smolin has authored or co-authored numerous scientific articles about
his ideas; here he presents them in non-technical language for
non-specialist readers. The book has two parts. The first describes and
criticises the predominant view, according to which past and future
exist and are fixed, and the second and longer part presents Smolin's
alternative opinion. The fixed view of time is often referred to as
Einstein's block universe. Einstein himself is said to have found
solace in the notion of timelessness: "People like us, who believe in
physics, know that the distinction between past, present, and future is
only a stubbornly persistent illusion."

Smolin experiences the emotional appeal of this understanding of time,
particularly in the way it has been developed by another physicist and
friend, Julian Barbour.

Barbour's theory of timeless quantum cosmology offers palpable
consolation for our mortality. I can feel it. I wish I could
believe it. You experience yourself in a collection of moments.
According to Barbour, that's all there is. Those moments always
are, eternally. The past is not lost. Past, present, and future
are with us, always. Your experience may figure in a finite set
of moments, but those moments never go away or cease. So nothing
comes to an end when you come to your last day. It's just that
now you are experiencing a moment that has all the memories
you will ever have. But nothing ceases, because nothing ever
started. The fear of death is based on an illusion, which in
turn is based on an intellectual mistake. There's no flow of
time running out, because there's no flow of time. There are
just, and always are, and always will be, the moments of your
life.

Appealing though Barbour's theory is, Smolin does not think it is
correct. Its picture of how the universe works is flawed, What we need
instead is a new cosmological theory. We do not have it yet but Smolin
outlines some of the features it will need to include. It will contain
the physics we already have, it will be scientific not metaphysical
(therefore making falsifiable predictions), it will explain why the
universe obeys the laws it does and not different laws, and it will
account for the initial conditions of our universe.

Scientific laws are not fixed but evolve, Smolin thinks, which leaves
room for at least a degree of genuine originality and innovation. The
future is not wholly predictable. But what influences how the laws
evolve? On this question we encounter a considerable surprise in
Chapter 12, where Smolin advances what he calls the Principle of
Precedence. This means that the laws form habits, so to speak, depending
on what has happened before. Smolin uses the analogy of the Anglo-Saxon
Common law, whereby judges act in the way that judges have done in the
past when presented with similar cases. Something of the kind might well
be operating in nature, he suggests.

When we do an experiment that we have carried out many times before and
in which we have always gotten the same result, we can reliably expect
that result in the future. … We can expect that the next time we throw
a ball it will travel along a parabola, which is what has happened every
time we have done this in the past. Usually we say that this is because
the motion is determined by a timeless law of nature, which being
timeless, will act in the future just as it has acted in the past. So
timeless laws preclude genuine novelty.

The Principle of Precedence would lead to the same result but would
leave open the possibility of change. Smolin says that, after
formulating this idea, he was astonished to find that it had been
anticipated by Charles Sanders Peirce, who spoke of the laws of nature
as habits developed over time. What I am reminded of is Rupert
Sheldrake's hypothesis of 'morphic resonance'. Widely derided by most
scientists, this has been taken up enthusiastically by adherents of
the New Age movement. If Smolin has noticed the resemblance he doesn't
mention it, but a quick search on the Net finds others who have.

Although Smolin insists that he is writing about science, not
metaphysics, there are definite philosophical implications in what he
says, notably in the passage about Julian Barbour quoted above. In an
epilogue he finds connections between a prevailing belief that reality
is timeless and threats to our survival, including climate change
and economic instability. And he concludes with a brief discussion of
the problem of consciousness, although the connection of this to the
subject of the book seems rather tenuous.

Smolin writes well for the non-specialist reader and the ideas he
discusses here are profound and important. How far they can be rendered
in words rather than mathematics is difficult to know. There is some
repetitiveness in the text and the argument is not always easy to
follow, but the central idea—that there are major difficulties with
the notion of timelessness that has characterised much of Western
thought since Plato—comes across clearly. The relevance of this for
theological speculations about the nature of God is only touched on
obliquely here and there, but such questions certainly arise if Smolin's
rejection of timelessness is right.